How to check the Realm file is present or not in realm database ? also want to check the schema is present in that particular realm

Question

Actually, I want to apply the check before opening the Realm is there is any way to check whether the path has provided is present in realm database or not also if present want to check whether the schema is already present or not like

consider having realm with name myrealm.realm

var realm = Realm.open({ path:'myrealm.realm', schema:[ { name: 'Dog', 
   properties: {name : 'string'}} , { name: 'Person', properties: { name : 
   'string'}} ]}).then( (realmInstance) => {
    realmInstance.objects('Customer').isValid() // this must return false as 
    customer is not present but it shows exception 
  })

Please suggest method to validate schema